Headache and Dizziness After a Car Accident: When Should You Be Rechecked?

“My X-ray was normal after a car accident, but I have a headache and feel dizzy. Is this part of recovery, or should I be checked again?”

Headache and dizziness alone do not identify one cause. They may occur with a neck or shoulder injury. They may also be symptoms of concussion when a sudden impact makes the head and brain move quickly, even without a direct blow to the head. The first step is to rule out a dangerous head injury before assessing the pain and recovery that remain.

Symptoms may appear later

Symptoms of mild traumatic brain injury, commonly called concussion, may begin immediately or appear hours or days later.

• Headache, dizziness, or balance problems
• Nausea or sensitivity to light or noise
• Feeling foggy or having trouble concentrating
• Fatigue or changes in sleep
• Irritability, emotional changes, or anxiety

These symptoms can occur in other conditions, so an online checklist cannot diagnose concussion. The accident, any loss of consciousness or memory gap, neurological examination, and current medicines all matter.

Does a normal X-ray mean the head is fine?

An X-ray mainly examines bone. Concussion is not diagnosed on an X-ray. This also does not mean that everyone with a headache after an accident needs CT or MRI.

A head CT is used when there is concern for an injury that must be identified promptly, such as bleeding in the brain. The decision is based on the full picture, including consciousness, vomiting, memory loss, neurological findings, and the use of blood-thinning medicines.

These signs require emergency assessment first

Go to an emergency department immediately if any of the following occurs after the accident:

• A headache that keeps worsening and does not go away
• Repeated vomiting
• Increasing drowsiness, difficulty waking, or confusion
• Slurred speech, weakness, numbness, or poor coordination
• A seizure, loss of consciousness, or unusual behavior
• One pupil becoming larger than the other or new double vision

Tell the clinician if you take an anticoagulant or certain antiplatelet medicines, have a gap in memory around the accident, or lost consciousness even briefly, even if you feel relatively well now.

Reassessment may still be needed after an emergency injury is excluded

Most mild concussion symptoms improve with time. However, see a healthcare provider again if symptoms have not improved after two to three weeks or worsen when you return to work, driving, exercise, or other activities.

Neck and shoulder pain, muscle tension, and sleep problems may remain after emergency injuries and concussion have been assessed. At that point, it is important not to assume either that “normal tests mean everything has healed” or that every post-accident symptom has one cause. The remaining problems need to be separated and assessed.

The accident may be over while recovery continues. The first priority, however, is not to mistake a delayed danger sign for an ordinary part of recovery.

See our care information for symptoms after a traffic accident

The Accident Ended, but the Body Did Not

References

• Symptoms and emergency danger signs of mild traumatic brain injury and concussion — U.S. Centers for Disease Control and Prevention, 2025
• Recovery after mild traumatic brain injury and when to seek follow-up care — U.S. Centers for Disease Control and Prevention, 2025
• Head injury: early assessment, hospital referral, and imaging criteria — NICE guideline NG232, 2023

Written by Dr. Ji-young Heo, KMD, PhD in Pathology of Korean Medicine; former Academic Research Professor of Herbal Pharmacology, Kyung Hee University